The present invention relates to slightly cross-linked polymers and copolymers generally derived from one or more unsaturated carboxylic acids, which are mixed with one or more active ingredients, and one or more excipients, wherein the mixture has desired properties such as good flow rates and appropriate compressibility so that without further processing it can flow through a die and be directly compressed into a tablet or other solid dosage article.
Heretofore, rheology agents were generally unsuitable for utilization in the formation of directly compressed tablets generally due to their fine particle size, static generating nature, and poor flow characteristics which they imparted to powder mixtures such as pharmaceutical mixtures. In order to form such powder mixtures, a rheologic agent in the form of a non-granulated powder was mixed with an active ingredient and an excipient and granulated. Subsequently, the granulated mixture was compressed into a tablet. The rheologic agents utilized included compounds such as Carbopol(copyright) 934 PNF, 971 PNF, 974 PNF, 940, 941, and 934 made by B.F. Goodrich Company. Other similar rheologic agents include Synthalen K, L, and M made by 3V/Sigma, Hivis Wako made by Wako Pure Chemicals Co., and Aqupec made by Sumitomo Seika.
Solid dosage forms such as tablets for pharmaceutical uses are directly compressed from a mixture of granular rheology modifying polymers or copolymers, active ingredients, and excipients. The rheology modifier is a homopolymer or copolymer derived from one or more unsaturated carboxylic acids and is slightly cross-linked. The rheology modifying polymer or copolymer is processed into a desirable granular size as by being compacted into large agglomerates or aggregates and subsequently fractured into smaller granules and generally screened to obtain suitable particle sizes which have low amounts of dust. The polymer or copolymer becomes highly swollen in an aqueous medium and is suitable for use in a human being or animal. The polymer or copolymer can be combined with numerous different types of active ingredients for one or more specific end uses. Moreover, numerous different types of excipients can be utilized. The combination of the one or more excipients, active ingredients, and the rheology modifying polymer or copolymer when mixed generally form suitable mixtures for directly compressible tablets because of their good flow characteristics and compressibility.